Change bool, and string properties to *bool, and *string for cc

there's no use case for prepending/appending to bool, and string
properties within module struct. Declearing "*bool" and "*string" almost
cover everything user need.

I did see one case that user specify relative_install_path as
path prefix in cc_defaults, and concatenate with the one in real module
to get the final relative install path in Android.bp <bionic/tests/libs>.

Test: m -j checkbuild
Bug: b/68853585
Change-Id: If3a7a2689c3fc307aae136af6bc9c57f27a1e1a0
diff --git a/cc/rs.go b/cc/rs.go
index 0e411aa..c2335dd 100644
--- a/cc/rs.go
+++ b/cc/rs.go
@@ -19,7 +19,6 @@
 	"strings"
 
 	"github.com/google/blueprint"
-	"github.com/google/blueprint/proptools"
 )
 
 func init() {
@@ -81,7 +80,7 @@
 }
 
 func rsFlags(ctx ModuleContext, flags Flags, properties *BaseCompilerProperties) Flags {
-	targetApi := proptools.String(properties.Renderscript.Target_api)
+	targetApi := String(properties.Renderscript.Target_api)
 	if targetApi == "" && ctx.useSdk() {
 		switch ctx.sdkVersion() {
 		case "current", "system_current", "test_current":